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Biomedical subjects

G Costa

Publications and source records attributed to G Costa.

At least 379 records · Page 21Linked to original sources
PubMedDate not supplied

Cholinomimetic drugs modify betamethasone suppression in the rat.

This study was performed to investigate the effect of different cholinomimetic drugs (CD) on ACTH levels in betamethasone (BET) pretreated rats (40 mg/kg in the drinking water for 24 h). Animals were injected with atropine methylbromide (1 mg/kg, i.p.) and, after 10 min, with physostigmine (25, 50, 100, 200 micrograms/kg), arecoline (AR) or oxotremorine (OX) (150, 300 micrograms/kg) intravenously. They were killed 10 and 20 min after CD injection, to measure ACTH plasma levels. The lowest dose of AR and both doses of OX were able to induce an escape from BET suppression. The hypothesis that a stimulation of central muscarinic (and, probably, not nicotinic) receptors is involved in the CD-induced escape from glucocorticoid suppression is discussed.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Release of atrial natriuretic factor induced by the A1 adenosine receptor agonist 2-chloro-N6-cyclopentyl-adenosine in the rat.

The effect of the adenosine receptor agonists, 2-chloro-N6-cyclopentyladenosine (CCPA) and 2-hexynyl-adenosine-5'-N-ethylcarboxamide (HENECA) on atrial natriuretic factor (ANF) release was investigated. The A1 adenosine receptor agonist CCPA markedly increased plasma ANF levels, following subcutaneous (s.c.), but not intracerebroventricular injection. ANF release evoked by the s.c. injection of CCPA was completely abolished by s.c. pretreatment with the selective A1 adenosine receptor antagonist, 1,3-dipropyl-8-cyclopentylxanthine. The A2 adenosine receptor agonist HENECA did not produce ANF release. The results of the present study suggest that peripheral adenosine mechanisms might be involved in the control of ANF secretion, through the activation of A1 adenosine receptors. Preliminary results show that CCPA produces ANF release also from isolated atria, thus suggesting that its action on ANF release is, at least in part, direct, and not only a consequence of cardiovascular modifications.

Adenosine↗
PubMedDate not supplied

A single-center experience of late retransplantation of the liver.

Liver retransplantation is considered to carry a higher risk than primary transplantation. However, there are an increasing number of retransplant candidates, especially owing to late graft failure. The aim of this study was to analyze a single-center experience in late liver retransplantation. The overall rate of primary retransplantation was 11.4% (28 re-OLT out of 245 primary OLT); the 14 (52%) who underwent retransplantation at more than 3 months after the first transplant were analyzed by a medical record review. Causes of primary graft failure leading to retransplantation were chronic hepatic artery thombosis in five cases (36%); recurrent HCV cirrhosis in four cases (29%); chronic rejection in two cases (14%); veno-occlusive disease; hepatic vein thrombosis or idiopathic graft failure in one case each (7%). UNOS status at re-OLT was always 2A, all patients were hospitalized; three were intensive care unit bound. ICU and total hospital stay had been 7 +/- 5 and 28 +/- 16 days, respectively. One- and 2-year patient and graft survivals were 84% and 62% and 67% and 67%, respectively. Death occurred in four patients. Two out of the three recovered in ICU at the time of retransplantation, at a median interval of 15 +/- 9 days after retransplantation. The survival rate after late retransplantation is improving, and this option should be considered to be a efficient way to save lives, especially by defining the optimal timing for retransplantation.

Adult↗
PubMedDate not supplied

Expressed sequence tags from poplar wood tissues--a comparative analysis from multiple libraries.

Xylogenesis involves successive developmental processes--cambial division, cell expansion and differentiation, cell death--each occurring along a gradient from the cambium to the pith of the stem. Taking advantage of the high level of organisation of wood tissues, we isolated cambial zone (CZ), differentiating xylem (DX) and mature xylem (MX) from both tension wood (TW) and opposite wood (OW) of bent poplars. Four different cDNA libraries were then constructed and used to generate 10,062 EST, reflecting the genes expressed in the different wood tissues. For the most abundant clusters, the EST distributions were compared between libraries in order to identify genes specific or over-represented at some specific developmental stages. They clearly showed a developmental shift between CZ and DX, whereas there is a continuity of development between DX and MX. CZ was mainly characterized by clusters of genes involved in cell cycle, protein synthesis and fate. Interestingly, two clusters with no assigned function were found specific to the cambial zone. In DX and MX, clusters were mostly involved in methylation of lignin precursors and microtubule cytoskeleton. In addition, in DX, EST from TW and OW were compared: five clusters of arabinogalactan proteins, one for sucrose synthase and one for fructokinase were specific or over-represented in TW. Moreover, a putative transcription factor and a cluster of unknown function were also identified in DX-TW. The informative comparison of multiple libraries prepared from wood tissues led to the identification of genes--some with still unknown functions--putatively involved in xylogenesis and tension wood formation.

Cell Cycle↗
PubMedDate not supplied

Hepatic regeneration after partial hepatectomy in mice infected with Schistosoma mansoni, at the acute and chronic phases of the disease.

Outbred male albino mice normal or infected with 30 cercariae of Schistosoma mansoni (LE strain) were submitted to 65% hepatectomy during the acute (70 days) and chronic phase (160 days) phases of the disease. A group of the infected animals was treated with 400 mg/kg of oxamniquine during the acute phase before hepatectomy. Non-infected, infected and treated but not hepatectomized animals were kept as controls. Hepatic regeneration was evaluated by incorporation of tritiated thymidine, intraperitoneally injected into non-hepatectomized and hepatectomized animals, 24 hours after surgery. The results showed that removal of 65% of the hepatic parenchyma, during the acute phase, led to a statistically significant increase of thymidine incorporation, when compared with the uninfected hepatectomized controls. This phenomenon was not observed at the chronic phase. Treatment with oxamniquine administered during the acute phase led to a decrease in thymidine incorporation rate 160 days after infection (90 days after treatment) and 24 hours after hepatectomy. The data suggest that infection with S. mansoni represents a considerable stimulus for the regenerative capacity of the liver during the acute, but not the chronic phase of disease.

Acute Disease↗
PubMedDate not supplied

[Association of thymoma and severe intestinal strongyloidiasis].

A 59-years-old man with thymoma and severe intestinal strongyloidiasis is reported. The authors pointed out a possible influence of immunological response related with thymoma in the development of hyperinfection by Strongyloides stercoralis.

Humans↗
PubMedDate not supplied

[Epidemiological surveillance of occupational pathology: a program of the Piedmont region (PRiOR). The PRiOR Protection Group].

A surveillance programme of exposures and health impairment from work (PRiOR) was developed in Piedmont Region during 1996-97, aiming to: (i) experiment and make available to the health and safety at work services methods and tools to detect currently under-reported cases of work related diseases (disease surveillance); (ii) and build up tools to predict exposure to occupational hazards (hazard surveillance). Within the framework of the disease surveillance system, an active search was carried out in hospital departments for sino-nasal cancer, pleuro-pericardial malignant mesotheliomas, bronchial asthma, and contact dermatitis (the last two diseases only when associated with hypersensitivity to agents possibly entailing occupational exposure). The programme tested and showed the feasibility of such a detection system on a regional basis; a pilot system was set up in order to collect the cases, assess them, and bring them to the attention of the health and safety at work services of the local health authorities. Case detection seems to have been rather complete, and time elapsed from first diagnosis has been kept to a minimum. The exposure histories of the collected cases show exposure patterns not only of historical, but also of current relevance. Evaluating the exposure status either by the occupational histories (neoplastic diseases) or by the hypersensitivity pattern and job title (allergic diseases), the proportion of occupationally exposed cases was remarkably high. At the end of the PRiOR programme, the active search procedures were considered to have yielded positive results. and are going to become a permanent surveillance system.

Feasibility Studies↗
PubMedDate not supplied

[Effects of octreotide (somatostatin analog SMS 201-995) on superior mesenteric artery blood flow in swine. An experimental study using Doppler color ultrasonography].

The effect of octreotide on splanchnic haemodynamics was investigated in 25 domestic pigs by mean of US-colordoppler. In a blind-operator design the superior mesenteric artery (SMA) blood flow was evaluated before and after i.m. injection of 5, 10, 20, 25 micrograms/kg or of an equivalent volume of saline solution. Seven serial measurements were taken every 10 min in each pig excluding the higher and the lower values. The administration of 5 and 10 micrograms/kg determined a rapid and stable (3 hours) decrease of the SMA blood flow (6 and 8.5% respectively) (p < 0.05). The blood flow decreased by 27-29% (p < 0.001) in response to the administration of 20 and 25 micrograms/kg respectively. The reduction started 30 min after injection and the blood flow remained lower than basal for up to 5 hours. Because of the mean standard error of US blood flow assessment is 10% due to the interobserver and intraobserver variations, we considered statistically significant only the reduction occurred after the administration of 20 or 25 micrograms/kg. Authors findings suggest that high dose of octreotide is effective in reducing the splanchnic haemodynamics in the pig. Such animal can be used in experimental setting planed to assess the effect of splanchnic blood flow reduction.

Analysis of Variance↗
PubMedDate not supplied

[The antistreptolysin activity of lysozyme].

The action of O-streptolysin on rabbit red corpuscles is inhibited by lysozyme, whereas the enzyme has no effect on termostable cytotoxic fraction of the toxin. Moreover little amounts of lysozyme canhance the anti-streptolysinic titers of human immune sera. These findings and the relationship between the biological activities of O-streptolysin are discussed.

Animals↗
PubMedDate not supplied

[Recurrent liver metastases from colorectal cancer: their surgical treatment].

Records of 8 patients undergoing repeated operation for isolated hepatic metastasis were reviewed for operative morbidity and mortality, survival, disease-free survival. The mean interval between the initial colon operation and first hepatic resection and that between the first and the second hepatic operation were calculated. Both were found to be correlated with survival of these patients. Repeat hepatic operation for recurrent colorectal metastasis to the liver yields comparable results to first hepatic resections in terms of operative mortality and morbidity, survival, disease-free survival. Repeated hepatic operation is the most successful for of treatment for isolated recurrent colorectal metastasis.

Adult↗
PubMedDate not supplied

[The so-called postcholecystectomy syndrome after laparoscopic intervention].

Preoperative symptoms have been found to persist in up to 30% of patients after open cholecystectomy. No data exists about the influence of laparoscopic cholecystectomy on symptoms. A group of 109 elective patients who had undergone at least 12 months previously laparoscopic cholecystectomy were retrospectively studied. Pre- and postoperative symptoms were compared and patients satisfaction graded from 1 (excellent) to 5 (worst). More than two symptoms were present preoperatively in all patients. Postoperatively 75 patients were absolutely symptomless. 9 patients complained of only one symptom, and 25 patients continued to have two or more symptoms. The mean time to return to full activity did not correlate with the number of postoperative symptoms. Most patients (75) considered the procedure completely successful while only 6 were no better off postoperatively. The incidence of symptoms after laparoscopic and laparotomic cholecystectomy is similar. The patients should be advised that the presence of preoperative symptoms are not necessarily caused by gallstones and that cholecystectomy might be followed by the persistence of symptoms.

Cholecystectomy, Laparoscopic↗